NOW ZAD, Afghanistan — Missiles, machine guns and strafing runs from fighter jets destroyed much of a Taliban compound, but the insurgents had a final surprise for a pair of U.S. Marines who pushed into the smoldering building just before nightfall.

As the two men walked up an alley, the Taliban opened fire from less than 15 yards, sending bullets and tracer fire crackling inches past them. They fled under covering fire from their comrades, who hurled grenades at the enemy position before sprinting to their armored vehicles.

The assault capped a day of fighting Saturday in the poppy fields, orchards and walled compounds of southern Afghanistan between newly arrived U.S. Marines and well dug-in Taliban fighters. It was a foretaste of what will likely be a bloody summer as Washington tries to turn around a bogged-down, eight-year-old war with a surge of 21,000 troops.

"This was the first time we pushed this far. I guess they don't like us coming into their back door," said Staff Sgt. Luke Medlin, who was sweeping the alley for booby traps as Marine Gunner John Daly covered him from behind when the Taliban struck.

"And now they know we will be back," said Medlin, from Richmond, Ind.

Symbol of what went wrongThe fighting was on the outskirts of Now Zad, a town that in many ways symbolizes what went wrong in Afghanistan and the enormous challenges facing the United States. It is in Helmand province, a center of the insurgency and the opium poppy trade that helps fund it.

Like much of Afghanistan, Now Zad and the surrounding area were largely peaceful after the 2001 invasion. The United Nations and other Western-funded agencies sent staff to build wells and health clinics.

But in 2006 — with American attention focused on Iraq — the insurgency stepped up in the south. Almost all the city's 35,000 people fled, along with the aid workers.

British and Estonian troops, then garrisoned in Now Zad, were unable to defeat the insurgents. They were replaced last year by a small company of about 300 U.S. Marines, who live in a base in the center of the deserted town and on two hills overlooking it.

The Taliban hold much of the northern outskirts and the orchards beyond, where they have entrenched defensive positions, tunnels and bunkers.

The Marines outnumber the Taliban in the area by at least 3-to-1 and have vastly superior weapons but avoid offensive operations because they lack the manpower to hold territory once they take it. There are no Afghan police or troops here to help.

"We don't have the people to backfill us. Why clear something that we cannot hold?" said Lt. Col. Patrick Cashman, head of the battalion in charge of Now Zad and other districts in Helmand and Farah provinces, where some 10,000 Marines are slowly spreading out in the first wave of the troop surge.

'A bad situation'Cashman said the Marines did not intend to allow the Taliban free rein in parts of Now Zad, but was unable to give any specific plans or time frame for addressing what he acknowledged is "a bad situation."

Saturday's mission was aimed at gathering intelligence and drawing a response from enemy positions close to a street called "Pakistani alley" because of one-time reports suggesting fighters from across the border had dug in there.

"We're bait," one Marine said as the convoy of five vehicles left the base at 8 a.m. and trundled north.

It quickly came across a roadside bomb — the kind which killed a member of the company on June 6 and has wounded at least seven others in the four weeks since the company has been stationed here. An engineer was dispatched and came back an hour later carrying the parts of the bomb — two 82mm mortar shells attached to a pressure plate.

Heading to inspect suspected tunnelThe vehicles were heading to inspect a suspected tunnel when the Taliban struck, firing mortars that landed close by. Machine gunners atop the vehicles and troops in an open-sided truck scanned the scene for plumes from weapons fire.

Hours of exchanges followed, with the Taliban opening fire with mortars, rocket-propelled grenades, machine-gun fire and rockets from the orchards or inside walled compounds.

A mortar punctured the tire of a Humvee; a grenade swooshed just over a troop truck.

"That was close," Daly said. "If they were a better shot, we'd be canceling Christmas."

Each time the insurgents attacked, the Marines returned fire if they could spot their foes or radioed in coordinates for air strikes.

"Bombs are away," a voice crackled over the radio as Dutch fighter jets dropped laser-guided bombs on a compound, sending clouds of dust mushrooming into the air. The planes then strafed the position, leaving a line of fire and destruction 50 yards long. Other times mortar teams back at the base in Now Zad pummeled enemy positions.

Final close callThe Marines left their vehicles twice. Each time, they came under attack as they entered maze-like, high-walled compounds with ill-fitting, aging wooden doors and small windows, ideal for sniper positions.

In the late afternoon, U.S. forces fired two missiles from 55 miles away to hit a compound being used by the attackers. Minutes later, Marine Harrier jets strafed the compound, setting fire to a wheat field outside it but sparing a poppy patch — an irony not lost on the troops.

The Marines got their final close call as they assessed the compound for damage.

After blowing a hole through the wall, Medlin and Daly were met by a hail of bullets as they pressed up an alley.

"Gunner, are you good? You need to come back!" one Marine shouted into the gathering gloom. "I'll cover you!"

The two man leapt to safety. Daly sprained his ankle as he leapt from a wall, but that was the only Marine injury.

Twenty minutes after the troops withdrew, two Cobra helicopters fired a Hellfire missile that streaked at a 45-degree angle across the night sky into the building, then bombed and strafed it, igniting a blaze.